Re: [mythtv-users] Pundit OR Pundit-R ?

[Jeroen Brosens]

Hi list, I really hope get some feedback from you :) I have the Pundit-non-R with the SiS video, very nice machine indeed, I have everything running smooth as silk on Gentoo Linux and MythTV 0.17, but there is one final thing: I am still trying to get the display of interlaced material right. The MPEG-2 streams from the PVR-250 are interlaced and so is a TV, so you would expect everything is OK. Yet the image from the TV-out still gives the comb-artifacts as a result of the interlaced material, which can be seen especially on horizontal movements. What is going on? On the extensive SiS X driver documentation pages (http://www.winischhofer.at/linuxsispart3.shtml#faq) I found this: Q: Why does output of interlaced video via TV show a "comb-like" "interlace"-effect? If the source material is interlaced and the TV output is interlaced, shouldn't this match? A: CRT2 does not support interlace. Therefore, the driver can't feed interlaced output into the video bridge (which handles TV output, be it a SiS video bridge, be it a Chrontel TV encoder). The video bridge can only convert a progressive scan (=non-interlaced) input into TV-suitable interlaced output. The driver can neither change this nor control which of the frames sent to the bridge is the even/odd field. Long story short: If you want to output interlaced material on your TV without using a software de-interlacer, you need to add a proper Modeline for interlaced PAL/NTSC timing (easily found on the internet) and an external VGA-to-TV converter connected to CRT1. Otherwise you have to use a software de-interlacer. So I thought I'd deinterlace the image with MythTV's built in bob deinterlacer, the only one that can keep the image's original frame rate (50 Hz for PAL and 59,94 Hz for NTSC). But whatever resolution or frame rate setting I try, the bob deinterlacer shows a vertical jitter every now and then, very annoying; the reason for this is that the software isn't aware of the Vsync frequency. nVidia users may use MythTV's OpenGL support for determining Vsync for this, but the SiS driver has NO OpenGL support in X. That just sucks donkey balls. And no, I don't want to use any of the other deinterlacers, because they don't provide full frame rate/fluid motion, so I am quite stuck there. Did anyone got the bob deinterlacer to work cleanly on the SiS X driver using Xv? Right now I am trying the next option, building a VGA-to-SCART converter cable (only available to PAL users, of course. Sorry USA/Japan.) This would theoretically bypass the TV-out and according to the quote above support interlaced material. I will keep you updated about my progress, because I finished the physical cable, but I must test it to see whether and if so, how it works. I made it myself for 5 euros because commercial ones cost 90. -- Jeroen

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